Generally, file allocation tables (FAT) store file locations by sector. However, FAT systems are notorious for corruption and fragmentation. New technology file system (NTFS) is another file system used by Windows®. NTFS is a journaling file system that uses an NTFS Log ($Logfile) to record metadata changes to the volume. However, file names are limited to 25 UTF-16 code words. Extended file system (EXT), currently version 4, can support volumes with sizes up to 1 exabyte and files with sizes up to 16 terabytes. However, these files systems are not stable and tend to fragment over time.